Flexible display device

ABSTRACT

A flexible display device is disclosed. The flexible display device includes a first layer and a second layer overlapping with the first layer. The first layer includes a plurality of first patterns, and the plurality of first patterns has a first pitch. The second layer includes a plurality of second patterns, and the plurality of second patterns has a second pitch. A ratio of the first pitch to the second pitch is greater than or equal to 2 and less than or equal to 200.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119 of ChineseApplication No. CN 201911310275.4 filed on Dec. 18, 2019, the disclosureof which is incorporated by reference.

BACKGROUND OF THE DISCLOSURE 1. Field of the Disclosure

The present disclosure relates to a flexible display device, and moreparticularly to a flexible display device with bending assistance.

2. Description of the Prior Art

In recent years, electronic devices or deformable electronic deviceshave become one of the focuses of the new generation electronictechnology. Therefore, the requirements for flexible display devicesthat can be integrated into electronic devices are also increasedaccordingly. The electronic device means that this device can be curved,folded, stretched, flexed or rolled, or may be deformed in othermethods. Since consumers have higher and higher requirements forflexible electronic devices, how to develop electronic devices withhigher reliability is one of the important issues for manufacturers.

SUMMARY OF THE DISCLOSURE

The present disclosure provides an electronic device, which may includea flexible display device with bending assistance to assist the flexureeffect of the flexible display device. In an embodiment, the flexurestability of the flexible display device may be increased through thedesign for the relative pitches of the patterns in different layers inthe flexible display device.

An embodiment of the present disclosure provides a flexible displaydevice. The flexible display device includes a first layer and a secondlayer overlapping with the first layer. The first layer includes aplurality of first patterns, and the plurality of first patterns has afirst pitch. The second layer includes a plurality of second patterns,and the plurality of second patterns has a second pitch, wherein a ratioof the first pitch to the second pitch is greater than or equal to 2 andless than or equal to 200.

These and other objectives of the present disclosure will no doubtbecome obvious to those of ordinary skill in the art after reading thefollowing detailed description of the embodiment that is illustrated inthe various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of the relative relationship between thetwo material layers of an electronic device according to the presentinvention.

FIG. 2 is a schematic diagram of the relative relationship between thetwo material layers of another embodiment of an electronic deviceaccording to the present invention.

FIG. 3 is a partial exterior schematic diagram of a first embodiment ofan electronic device according to the present disclosure.

FIG. 4 is a partial exterior schematic diagram of a variation of thefirst embodiment of the electronic device according to the presentinvention.

FIG. 5 is a partial top-view schematic diagram of the first embodimentof an electronic device according to the present disclosure.

FIG. 6 is a partial sectional-view schematic diagram of the firstembodiment of an electronic device according to the present disclosure.

FIG. 7 is a partial sectional-view schematic diagram of a secondembodiment of an electronic device according to the present disclosure.

FIG. 8 is a partial sectional-view schematic diagram of a thirdembodiment of an electronic device according to the present disclosure.

FIG. 9 is a partial sectional-view schematic diagram of a fourthembodiment of an electronic device according to the present disclosure.

FIG. 10 is a partial sectional-view schematic diagram of a fifth of anelectronic device according to the present disclosure.

FIG. 11 is a partial top-view schematic diagram of various examples ofassisting patterns of an electronic device according to the presentdisclosure.

FIG. 12 is a partial sectional-view schematic diagram of a first variantembodiment of an assisting layer of an electronic device according tothe present disclosure.

FIG. 13 is a partial sectional-view schematic diagram of a secondvariant embodiment of an assisting layer of an electronic deviceaccording to the present disclosure.

FIG. 14 is a partial sectional-view schematic diagram of a third variantembodiment of an assisting layer of an electronic device according tothe present disclosure.

FIG. 15 is a top-view schematic diagram of an assisting layer of anotherembodiment of an electronic device according to the present disclosure.

DETAILED DESCRIPTION

The present disclosure may be understood by reference to the followingdetailed description, taken in conjunction with the drawings asdescribed below. It is noted that, for purposes of illustrative clarityand being easily understood by the readers, various drawings of thisdisclosure show a portion of the display device, and certain elements invarious drawings may not be drawn to scale. In addition, the number anddimension of each element shown in drawings are only illustrative andare not intended to limit the scope of the present disclosure.

Certain terms are used throughout the description and following claimsto refer to particular components. As one skilled in the art willunderstand, electronic equipment manufacturers may refer to a componentby different names. This document does not intend to distinguish betweencomponents that differ in name but not function.

In the following description and in the claims, the terms “include” and“comprise” are used in an open-ended fashion, and thus should beinterpreted to mean “include, but not limited to . . . ”.

It should be understood that when an element or layer is referred to asbeing “on” or “connected to” another element or layer, it may bedirectly on or directly connected to the other element or layer, orintervening elements or layers may be presented (indirect condition). Incontrast, when an element is referred to as being “directly on” or“directly connected to” another element or layer, there are nointervening elements or layers presented.

Although terms such as first, second, third, etc., may be used todescribe diverse constituent elements, such constituent elements are notlimited by the terms. The terms are used only to discriminate aconstituent element from other constituent elements in thespecification. The claims may not use the same terms, but instead mayuse the terms first, second, third, etc. with respect to the order inwhich an element is claimed. Accordingly, in the following description,a first constituent element may be a second constituent element in aclaim.

The terms “substantially” typically mean+/−20% of the stated value, moretypically+/−10% of the stated value, more typically+/−5% of the statedvalue, more typically+/−3% of the stated value, more typically+/−2% ofthe stated value, more typically+/−1% of the stated value and even moretypically+/−0.5% of the stated value. The stated value of the presentdisclosure is an approximate value. When there is no specificdescription, the stated value includes the meaning of “substantially”.Moreover, when considering the deviation or the fluctuation of themanufacturing process, the term “same” may also include the meaning of“substantially”.

It should be noted that the technical features in different embodimentsdescribed in the following can be replaced, recombined, or mixed withone another to constitute another embodiment without departing from thespirit of the present disclosure.

Please refer to FIG. 1. FIG. 1 is a schematic diagram of the relativerelationship between two material layers of an electronic deviceaccording to the present invention. As shown in FIG. 1, an electronicdevice ED of the present disclosure may be a flexible electronic device,wherein the term “flexible” means that the electronic device ED may becurved, bent, folded, rolled, flexed, stretched, and/or other similarlydeformed, and the deformation described above is represented by“flexible” hereinafter. The electronic device ED may include a displaydevice, an antenna device, a sensor device or a tiled device, but notlimited herein. The electronic device may for example include liquidcrystal, fluorescence, phosphor, light emitting diode, other suitabledisplay medium or any combination thereof, but not limited herein. Thelight emitting diodes (LEDs) may for example include organic lightemitting diodes (OLEDs), mini LEDs, micro LEDs, nano wire LEDs, bar typeLEDs, quantum dot LEDs (QLEDs, QDLEDs) or LEDs with any other suitablematerials, and these materials may be disposed in any arrangement orcombination, but not limited herein. The antenna device may be a liquidcrystal antenna, but not limited herein. The tiled device may be adisplay tiled device or an antenna tiled device, but not limited herein.It is noted that the electronic device may be any arrangements orcombinations of the devices described above, but not limited herein. Inthe following description, a display device is used as the electronicdevice to illustrate the content of the present disclosure. That is tosay, the electronic device ED in the following description for examplehas display function and includes a flexible display device 100 havingdisplay elements, but the present disclosure is not limited herein. Theflexible display device 100 includes a first layer LR1 and a secondlayer LR2. The second layer LR2 overlaps with the first layer LR1 in avertical direction Dz, that is, at least a part of the second layer LR2overlapping with the first layer LR1. In the structure of FIG. 1, thefirst layer LR1 is disposed on the second layer LR2 in the direction Dz.For example, when the flexible display device 100 includes a flexiblesubstrate 102 and the first layer LR1 and the second layer LR2 are bothdisposed on the flexible substrate 102 (i.e., the flexible displaydevice 100 includes a flexible substrate 102 thereon disposed the firstlayer LR1 and the second layer LR2), the second layer LR2 is disposedbetween the first layer LR1 and the flexible substrate 102. However, ina variant embodiment, the first layer LR1 may also be disposed below thesecond layer LR2. The first layer LR1 includes a plurality of firstpatterns LP1 extending along a direction Dy and being arranged side byside along a direction Dx, and each first pattern LP1 has a first pitchPt1 and a first width (which is the line width of the first patternLP1). The second layer LR2 includes a plurality of second patterns LP2,and each second pattern LP2 has a second pitch Pt2 and a second width(which is the line width of the second pattern LP2), wherein the firstpitch Pt1 is greater than the second pitch Pt2, and a ratio of the firstpitch Pt1 to the second pitch Pt2 is greater than or equal to 2 and lessthan or equal to 200. In the range described above, the optical rippleinterference between the first layer LR1 and the second layer LR2 may bereduced, and better display performance may be provided. In someembodiments, the range of the first pitch Pt1 may for example be greaterthan 40 micrometers (μm) and less than or equal to 4000 μm, but notlimited herein. In some embodiments, the first layer LR1 may be used asan assisting layer BSL. The term “assisting layer” in the presentdisclosure refers to that it is helpful to make the flexible displaydevice 100 be flexed or bent toward a direction perpendicular to theextending direction (e.g., the direction Dy) of the patterns (referredto as assisting patterns, or first patterns LP1 for example) of theassisting layer BSL. The second patterns LP2 may be any conducting linesin the display layer or the touch layer, such as (but not limited to)scan lines or a data lines, or may be any one of power supply lines,common voltage lines, data lines, scan lines, signal reference lines ortouch signal lines. In some embodiments, one of the plurality of firstpatterns LP1 has a first width (or referred to as first line width), oneof the plurality of second patterns LP2 has a second width (or referredto as second line width), and a ratio of the first width to the firstpitch Pt1 is less than a ratio of the second width to the second pitchPt2. For example, the ratio of the second width to the second pitch Pt2may be greater than or equal to 0.02 and less than or equal to 0.2.

Please refer to FIG. 2. FIG. 2 is a schematic diagram of the relativerelationship between two material layers of another embodiment of anelectronic device according to the present invention. According to thepresent disclosure, the pattern pitch of the upper material layer mayalso be less than the pattern pitch of the lower material layer. In thestructure shown in FIG. 2, the second layer LR2 is disposed on the firstlayer LR1. That is to say, the pitch of the upper material layer (thesecond pitch Pt2) is less than the pitch of the lower material layer(the first pitch Pt2), but the ratio of the first pitch Pt1 to thesecond pitch Pt2 is still greater than or equal to 2 and less than orequal to 200. The second pitch Pt2 may range from 0.1 μm to 40 μm, forexample, from 0.1 μm to 10 μm, and the first pitch Pt1 may range from 10μm to 20 μm, for example, 20 μm, but not limited herein. In someembodiments, the second layer LR2 may be used as the assisting layerBSL, which is helpful to make the flexible display device 100 be flexedor bent toward a direction perpendicular to the extending direction(e.g., the direction Dy) of the patterns (referred to as assistingpatterns, or second patterns LP2 for example) of the assisting layerBSL. In some embodiments, the second layer LR2 may be used as a rasterelement. The raster element for example may provide functions such aspolarization, collimation and/or privacy protection, but not limitedherein. In some embodiments, the raster element may be, for example, awire grid polarizer (WGP). The first patterns LP1 may be any conductinglines in the display layer or the touch layer, such as (but not limitedto) scan lines or a data lines, or may be any one of power supply lines,common voltage lines, data lines, scan lines, signal reference lines ortouch signal lines. In some embodiments, one of the plurality of firstpatterns LP1 has a first width, one of the plurality of second patternsLP2 has a second width, and a ratio of the first width to the firstpitch Pt1 is less than a ratio of the second width to the second pitchPt2. For example, the ratio of the second width to the second pitch Pt2may be greater than or equal to 0.3 and less than or equal to 3, forexample, greater than or equal to 0.3 and less than or equal to 0.8, andthe ratio of the first width to the first pitch Pt1 may be greater thanor equal to 0.02 and less than or equal to 0.2. In the ranges describedabove, the effect of using the second layer LR2 as the assisting layerBSL may be more obvious, the optical ripple interference between thefirst layer LR1 and the second layer LR2 may also be reduced, and betterdisplay effects may be provided.

The applications, structures and materials of the assisting layer BSLand the assisting patterns BSP in the electronic devices or the flexibledisplay devices will be described in various embodiments in thefollowing.

Please refer to FIG. 3 to FIG. 6. FIG. 3 is a partial exterior schematicdiagram of a first embodiment of an electronic device according to thepresent disclosure. FIG. 4 is a partial exterior schematic diagram of avariation of the first embodiment of the electronic device according tothe present invention. FIG. 5 is a partial top-view schematic diagram ofthe first embodiment of an electronic device according to the presentdisclosure. FIG. 6 is a partial sectional-view schematic diagram of thefirst embodiment of an electronic device according to the presentdisclosure. As shown in FIG. 3, the flexible display device 100 may havea flexible substrate 102 and an assisting layer BSL. The assisting layerBSL may be disposed on a surface of the flexible substrate 102 andinclude a plurality of assisting patterns BSP. The flexible substrate102 has at least one flexing axis FX substantially parallel to theextending direction of the assisting patterns BSP (e.g., the directionDy), and a part of the flexible substrate 102 may be bent or rolled atleast toward a direction perpendicular to the direction Dy (e.g., thedirection Dz), for example curved along the direction of the arrow AR.Alternatively, a part of the flexible substrate 102 for example may berolled by taking the flexing axis FX as the axis center, but thedeformation and flexing manner of the flexible substrate 102 are notlimited to the above. Please refer to FIG. 4, in a variation of thefirst embodiment of the present disclosure, a part of the flexiblesubstrate 102 may be bent along at least one direction, and the bentportion can define a flexing axis FX.

Please refer to FIG. 3 and FIG. 5. The flexible substrate 102 may betransparent or opaque, and the material of the flexible substrate mayinclude polymer materials such as polyimide (PI), polycarbonate (PC),polyethylene terephthalate (PET) and/or adhesive materials, but notlimited herein. The flexible substrate 102 may also include thin glassor any suitable materials. The assisting layer BSL may provide suitablesupport for the flexible substrate 102 without affecting the flexibilityof the flexible substrate 102. In detail, the assisting patterns BSP ofthe assisting layer BSL may provide the flexible display device 100 witha function like a bracket. The function of the assisting patterns BSP ofthe assisting layer BSL may assist in adjusting the bending direction orthe flexing direction of the flexible substrate 102, so that theflexible substrate 102 may be bent toward a predetermined direction, andthe stress in the non-bending direction can be reduced so as to mitigatethe abnormal display problems. The assisting patterns BSP may becomposed of any material suitable for being integrated into the flexibledisplay device 100, for example using materials that may be cooperatedwith the processes of the light emitting layer, the circuit layer, thebonding layer, the light shielding layer, the light adjusting layer, thetouch layer, the insulating layer and/or the protecting layer in theflexible display device 100. For example, the material of the assistinglayer BSL may include, but not limited to, metals (e.g., copper oraluminum), black matrix (BM) materials or organic polymer materials. Theassisting patterns BSP may be manufactured by printing, coating or othersuitable methods.

In the assisting layer BSL shown in FIG. 3 (or FIG. 4), the assistingpatterns BSP are generally uniformly distributed on the surface of theflexible substrate 102 and arranged side by side along the direction Dx,wherein the direction Dx intersects with the extending direction of theflexing axis FX (i.e., the direction Dy). For example the direction Dxperpendicular to the extending direction of the flexing axis Fx. In thedirection Dx, the same line spacings Ds may exist between the adjacentassisting patterns BSP, and all of the assisting patterns BSP may havethe same line width Ws, wherein the pitch Ps is the sum of one linespacing Ds and one line width Ws. The definition of the pitch Ps may bemeasured from the center of an assisting pattern BSP to the center ofanother adjacent assisting pattern BSP, or from the edge at a side of anassisting pattern BSP to the edge at the same side of another adjacentassisting pattern BSP. It should be noted that, the design for theassisting patterns BSP of the present disclosure is not limited to thoseshown in FIG. 3 and FIG. 4. The plurality of assisting patterns BSP inone assisting layer BSL may have different patterns, different linewidths Ws and/or different line spacings Ds. Furthermore, the assistingpatterns BSP may not be uniformly distributed on the flexible substrate102. For example (but not limited to), the assisting patterns BSP in oneregion on the flexible substrate 102 (for example, but not limited to,the region farther away from the flexing axis FX) may be denselydistributed, while the assisting patterns BSP in another region on theflexible substrate 102 (for example, but not limited to, the regioncloser to the flexing axis FX) may be loosely distributed. When thedistribution of the assisting patterns BSP is not uniform, the pitch Psof the assisting patterns BSP may be obtained by averaging the pitchesPs of all of the assisting patterns BSP in the assisting layer BSL, orby averaging the pitches Ps of five of the assisting patterns BSP, butnot limited herein. In addition, according to the present disclosure,the distribution region of the assisting layer BSL may be defined byconnecting the outermost edges of each assisting pattern BSP.

Please refer to FIG. 5. The flexible display device 100 may furtherinclude another material layer CLL disposed on the flexible substrate102. The material layer CLL may be disposed on the assisting layer BSL(i.e., the assisting layer BSL is disposed between the material layerCLL and the flexible substrate 102), or the assisting layer BSL may bedisposed on the material layer CLL (i.e., the material layer CLL isdisposed between the assisting layer BSL and the flexible substrate102). In other words, the present disclosure does not limit the relativepositions of the material layer CLL and the assisting layer BSL on thesurface of the flexible substrate 102 or in the direction DZ. In FIG. 5,the material layer CLL is illustrated on the assisting layer BSL as anexample, but the present disclosure is not limited to that shown in FIG.5. The material layer CLL may include a plurality of wire patterns 108substantially extending along the direction Dy and having a pitch Pc,wherein the pitch Pc of the wire patterns 108 may be defined in a methodsimilar to the pitch Ps of the assisting patterns BSP, which will not beredundantly described. In the structure shown in FIG. 5, the pitch Pc isdifferent from the pitch Ps, and a ratio of the pitch Ps to the pitch Pcis greater than or equal to 2 and less than or equal to 200. This designmay provide both of the flexibility and the support and reduce opticalripple interference, so as to provide better display effects. Preciselyspeaking, the material layer CLL may be included in the display layer114 (shown in FIG. 6), and the wire patterns 108 may be used as aplurality of wires in the display layer 114, for example, fortransmitting signals or providing voltages. The display layer 114 mayfurther include a light emitting layer 104 formed of a plurality oflight emitting units 106, and the corresponding region of each lightemitting unit 106 may be regarded as a sub-pixel to define a displayregion 110 of the flexible display device 100. According to the presentdisclosure, the distribution region (or referred to as the distributionarea) of the assisting layer BSL may be greater than the area of thedisplay region 110. As shown in FIG. 5, in the direction Dx, the minimumdistance between an edge 102E of the flexible substrate 102 generallyparallel to the flexing axis FX and an outermost side of the assistingpatterns BSP closest to the edge 102E is defined as an edge distance E1.The minimum distance between the light emitting layer 104 or the displayregion 110 and the edge 102E is defined as an edge distance E2, and theedge distance E2 is greater than the edge distance E1. In other words,in the direction Dx, the outermost assisting pattern BSP may be closerto the edge 102E than the display region 110. For example, in thedirection (e.g., the direction Dz) perpendicular to the surface of theflexible substrate 102, at least a part of the assisting patterns BSPmay be disposed outside the display region 110, or at least a part ofthe assisting layer BSL may not overlap with the display region 110 orthe light emitting layer 104.

Please refer to FIG. 6, the lower side of the flexible substrate 102 mayfurther include an adhesive layer 122 and a supporting film 124, whereinthe flexible substrate 102 may be attached to the surface of thesupporting film 124 through the adhesive layer 122, so that the flexiblesubstrate 102, the adhesive layer 122 and the supporting film 124 form asubstrate structure. In some embodiments, the flexible substrate 102 andthe supporting film 124 may respectively include materials such aspolyethylene terephthalate (PET), polyimide (PI) or polyethylenenaphthalate (PEN), but not limited herein. A display layer 114 may bedisposed on the flexible substrate 102, and the display layer 114 mayinclude a circuit layer 112 and a light emitting layer 104. The circuitlayer 112 may include electronic elements such as wires, drivingelements, switch elements, reset elements, compensation elements,operation control elements and capacitors, so as to drive the lightemitting layer 104 to emit light. For example, the circuit layer 112includes a plurality of driving elements 132 arranged in a matrix. Thedriving elements 132 in FIG. 6 are represented by thin film transistors,but are not limited herein. The light emitting layer 104 includes aplurality of light emitting units 106, and each driving element 132 maybe electrically connected to a corresponding light emitting unit 106 todrive the corresponding light emitting unit 106. FIG. 6 shows that thedriving element 132 may at least partially overlap with thecorresponding light emitting unit 106 in the vertical direction (thedirection Dz) of the surface of the flexible substrate 102, but notlimited herein.

The light emitting element 106 may include any kind of display medium orlight emitting elements such as organic light-emitting diodes (OLEDs),micro light-emitting diodes (micro-LEDs), mini light-emitting diodes(mini-LEDs), quantum dot LEDs (QLEDs), nano wire LEDs or bar type LEDs,but not limited herein. For example, the light emitting unit 106includes a first electrode 106 a, a second electrode 106 c and a displaymedium layer 106 b disposed between the first electrode 106 a and thesecond electrode 106 c. For example, the first electrode 106 a may bethe anode of the light emitting unit 106 and the second electrode 106 cmay be the cathode of the light emitting unit 106, but not limitedherein. The light emitting region of each light emitting unit 106 may bedefined by an insulating layer 134 used as a pixel defining layer (PDL).The display medium layer 106 b may include one or more than one layersof emissive materials, and the emissive materials may be organic orinorganic materials. The different light emitting units 106 may emitlight of different colors, such as red, green and blue. For example, thedisplay medium layers 106 b of different light emitting units 106 may bemade of different materials so as to emit red light, green light andblue light respectively. In some embodiments, the display medium layers106 b of different light emitting units 106 may be made of the samematerial to emit the same light. The first electrode 106 a and thesecond electrode 106 c may include metals or transparent conductivematerials, but not limited herein. The metal material of the electrodesmay include, but not limited to, magnesium, calcium, aluminum, silver,tungsten, copper, nickel, chromium, or combinations of the materialsdescribed above or alloys of one or more of the materials describedabove. The transparent conductive material may include, for example,indium tin oxide, indium zinc oxide, zinc oxide, indium oxide orcombinations of any materials described above, but not limited herein.In addition, the surface of the light emitting unit 106 may be coveredwith an insulating layer 140 as a protecting layer. In some embodiments,the display medium layer 106 b may be, for example, liquid crystalmaterials. In other embodiments, the flexible display device 100 mayfurther include a color filter layer (not shown in the drawings) and ablack matrix (not shown in the drawings) disposed on the light emittingunit 106, but not limited herein.

In the present embodiment, the driving element 132 may be a top-gatetype thin film transistor (TFT), but not limited herein. The bottom-gatetype thin film transistors or other suitable electronic elements may beused in other embodiments, and in the flexible display device 100, thestructures of the thin film transistors may not be limited to only onetype. The driving device 132 may include a semiconductor layer 132C, adielectric layer 1321, a gate 132G a dielectric layer 136, a drain 132Dand a source 132S. The semiconductor layer 132C may be formed ofsemiconductor materials, such as silicon or metal oxide, but not limitedherein. For example, the semiconductor layer 132C may be an amorphoussilicon layer, a polysilicon layer or an indium gallium zinc oxide(IGZO) layer. Furthermore, in a driving device 132, the semiconductorlayer 132C includes a source contact, a drain contact and a channeldisposed between the source contact and the drain contact. The source132S is electrically connected to the corresponding source contactthrough an interlayer hole of the dielectric layer 136 and thedielectric layer 1321. The drain electrode 132D is electricallyconnected to the corresponding drain contact through another interlayerhole of the dielectric layer 136 and the dielectric layer 1321. The gate132G is isolated from the semiconductor layer 132C through thedielectric layer 1321 as a gate insulating layer in the driving element132. The gate 132G the source 132S and the drain 132D may be formed ofconductive materials (e.g., metals), but not limited herein. Thematerials suitable for forming the gate 132G, the source 132S and thedrain 132D may refer to the materials for forming the first electrode106 a and the second electrode 106 c described above. In the presentdisclosure, a driving element 132 may be electrically connected to thecorresponding light emitting unit 106 through the drain 132D to drivethe light emitting unit 106. Precisely speaking, the drain 132D may bedirectly connected to the first electrode 106 a of the light emittingunit 106. In addition, the dielectric layer 138 may be disposed betweenthe first electrode 106 a of the light emitting unit 106 and theconductive layer forming the source 132S and the drain 132D.

Furthermore, a buffer layer 148 may be disposed between the flexiblesubstrate 102 and the display layer 114. The buffer layer 148 mayinclude, for example, an oxide layer, a nitride layer or other suitableinsulating layer, but not limited herein. Moreover, an encapsulatinglayer 142 may be disposed on the display layer 114. The encapsulatinglayer 142 may provide protection, encapsulation and/or planarizationfunctions for the display layer 114, and the encapsulating layer 142 mayinclude organic materials, inorganic materials, the arrangementcombinations or mixtures of the above, but not limited herein. Forexample, the encapsulating layer 142 may be a multi-layer structureincluding an inorganic layer, an organic layer and an inorganic layer.In some embodiments, the encapsulating layer 142 may be replaced byanother flexible substrate (not shown in the drawings), and a colorfilter layer and/or a black matrix may be disposed on this flexiblesubstrate, but not limited herein. In another aspect, the flexibledisplay device 100 may further have touch function, such as selectivelyincluding a touch layer 120. The conductive layer 116 in the touch layer120 may be used to form touch elements 116 a and/or touch signal lines,and the insulating layer 118 may cover the conductive layer 116. In thedirection Dz, the arrangement of the touch elements 116 a and the touchsignal lines may not cover the light emitting regions of the lightemitting units 106, or at least a part of the touch elements 116 a andthe touch signal lines may not be overlapped with the light emittingunits 106, but not limited herein. In addition, a polarizing layer 126may be selectively disposed on the touch layer 120, wherein thepolarizing layer 126 for example includes organic material, and atransparent covering layer 128 may further be selectively disposed onthe polarizing layer 126, wherein the transparent covering layer 128 forexample includes such glass or organic material, but the presentdisclosure is not limited to the above.

In FIG. 6, the assisting layer BSL is disposed on the display layer 114and the touch layer 120 and disposed below the polarizing layer 126,that is, the assisting layer BSL is disposed between the touch layer 120and the polarizing layer 126. In addition, an insulating layer 130having the function of a planar layer may be disposed on the assistinglayer BSL. In the direction Dz, each assisting pattern BSP maycorrespondingly overlap with a touch element 116 a, and each assistingpattern BSP may correspondingly overlap with the PDL insulating layer134 to expose the light emitting unit 106, so as to increase theaperture ratio. The distribution density of the assisting patterns BSPmay be smaller than the distribution density of the touch elements 116a, but the present disclosure is not limited herein. For example, insome embodiments, each touch element 116 a may respectively correspondto an assisting pattern BSP. In addition, in the structure shown in FIG.6, the conductive layer used to form the gate 132G may be regarded asthe material layer CLL mentioned in FIG. 5, and the wire patterns 108(shown in FIG. 5) included in the material layer CLL for example serveas scan lines of the display layer 114, but not limited herein. In otherembodiments, the wire patterns 108 may also be one of power supplylines, common voltage lines, data lines, signal reference lines andtouch signal lines. In this embodiment, the assisting layer BSL maycorrespond to the first layer LR1 in FIG. 1, the assisting patterns BSPmay correspond to the first patterns LP1 in FIG. 1, the pitch Ps maycorrespond to the first pitch Pt1 in FIG. 1, the material layer CLL maycorrespond to the second layer LR2 in FIG. 1, the wire patterns 108 maycorrespond to the second patterns LP2 in FIG. 1, and the pitch Pc maycorrespond to the second pitch Pt2 in FIG. 1. In addition, the ratio ofthe first pitch Pt1 to the second pitch Pt2 is greater than or equal to2 and less than or equal to 200. This design may provide both of theflexibility and the support and reduce optical ripple interference, soas to provide better display effects. Furthermore, the line width Ws ofone of the first patterns is defined as a first width, and the linewidth Wc of one of the second patterns is defined as a second width. Theratio of the first width (i.e., the first width Ws) to the first pitchPs (i.e., the pitch Ps) is less than the ratio of the second width(i.e., the line width Wc) to the second pitch (i.e., the pitch Pc). Insome embodiments, the ratio of the second width to the second pitch isgreater than or equal to 0.02 and less than or equal to 0.2, but notlimited herein. From the above description, it should be understand thatthe first layer is disposed on the second layer in this embodiment, thatis, the second layer is disposed between the flexible substrate and thefirst layer. For example, the first pitch Ps may range from 40 μm to4000 μm, and the second pitch Pc may range from 1 μm to 20 μm.

It should be noted that, the structure of the flexible display device100 of the present disclosure is not limited to the above description,and the assisting layer BSL may be disposed at other suitable positionsof the sectional structure.

In the following description, other embodiments or variant embodimentsof the present disclosure will be described. For simplifying theillustration, the same films or elements in the following embodimentswill be represented with the same symbols, and the features thereof willnot be described redundantly. The differences between variousembodiments will be described in detail below.

Please refer to FIG. 7. FIG. 7 is a partial sectional-view schematicdiagram of a second embodiment of an electronic device according to thepresent disclosure. In some embodiments, the assisting patterns BSP ofthe assisting layer BSL are disposed on the polarizing layer 126 and thedisplay layer 114. In addition, in the structure shown in FIG. 7, thetouch layer 120 may not include the insulating layer 118, and theconductive layer 116 forming the touch elements 116 a is directlydisposed on the encapsulating layer 142. The flexible display device 100further includes another encapsulating layer 144 directly covering andcontacting the touch elements 116 a, and the encapsulating layer 144 isdisposed between the assisting layer BSL and the touch elements 116 a.The encapsulating layer 144 is, for example (but not limited to), anorganic material layer with a greater thickness, so that the distancebetween the assisting layer BSL and the touch layer 120 may be greaterin the direction Dz. When the assisting layer BSL includes metalmaterials, this design may reduce the effect of the assisting layer BSLon sensing signals by the touch elements 116 a or transmitting signalsby the touch signal lines. The distribution density of the assistingpatterns BSP in FIG. 7 is greater than the distribution density of theassisting patterns BSP in FIG. 6, and the pitch Ps in FIG. 7 is lessthan the pitch Ps in FIG. 6. For example, an assisting pattern BSP maycorrespond to a touch element 116 a or a touch wire, but the presentdisclosure is not limited herein. For example, the assisting layer BSL,the assisting patterns BSP and the pitch Ps may correspond to the firstlayer, the first patterns and the first pitch in FIG. 1 or FIG. 2.Furthermore, any kind of wires in the flexible display device 100 thatare substantially parallel to the assisting patterns BSP may be regardedas the second patterns in FIG. 1 or FIG. 2, and the material layerforming these wires and the pitch of these wires may correspond to thesecond layer and the second pitch in FIG. 1 or FIG. 2, wherein the firstpitch is different from the second pitch, and the ratio of the firstpitch to the second pitch is greater than or equal to 2 and less than orequal to 200. In another example, the assisting layer BSL, the assistingpatterns BSP and the pitch Ps may correspond to the second layer, thesecond patterns and the second pitch in FIG. 1 or FIG. 2. Furthermore,any kind of wires in the flexible display device 100 that aresubstantially parallel to the assisting patterns BSP may be regarded asthe first patterns in FIG. 1 or FIG. 2, and the material layer formingthese wires and the pitch of these wires may correspond to the firstlayer and the first pitch in FIG. 1 or FIG. 2, wherein the first pitchis different from the second pitch, and the ratio of the first pitch tothe second pitch is greater than or equal to 2 and less than or equal to200. For example, when the ratio of the pitch Ps of the assistingpatterns to the wire pitch formed by the material layer forming thesewires is greater than or equal to 2 and less than or equal to 200, theassisting layer BSL may be regarded as the first layer in FIG. 1 or FIG.2, and the material layer may be regarded as the second layer in FIG. 1or FIG. 2. On the other hand, when the ratio of the wire pitch formed bythe material layer forming these wires to the pitch Ps is greater thanor equal to 2 and less than or equal to 200, the assisting layer BSL maybe regarded as the second layer in FIG. 1 or FIG. 2, and the materiallayer may be regarded as the first layer in FIG. 1 or FIG. 2. Under theconditions described above, the assisting layer BSL may provide thesupport function as mentioned above, which is helpful to make theflexible display device 100 be flexed toward a predetermined direction,and reduce the stress effects generated during bending in otherdirections. If the assisting patterns BSP have a smaller pitch Ps and alarger line width Ws, good support effects may be provided. However, ifthe pitch Ps is too small and the line width Ws is too large, theoverall flexibility of the flexible display device 100 may be reduced.Therefore, the design of the present disclosure makes the pitch of theassisting patterns BSP satisfy the above design, so as to provide thedesired flexibility and support effects.

Please refer to FIG. 8. FIG. 8 is a partial sectional-view schematicdiagram of a third embodiment of an electronic device according to thepresent disclosure. In some embodiments, the assisting patterns BSP ofthe assisting layer BSL are disposed on the upper surface 1021 of theflexible substrate 102, that is, the assisting layer BSL is disposedbetween the flexible substrate 102 and the display layer 114.Furthermore, the polarizing layer 126 may directly contact the touchlayer 120, for example, disposed on the upper surface of the insulatinglayer 118 in the touch layer 120. The assisting layer BSL, the assistingpatterns BSP and the pitch Ps may respectfully correspond to the firstlayer, the first patterns and the first pitch in FIG. 1 or FIG. 2, ormay respectfully correspond to the second layer, the second patterns andthe second pitch in FIG. 1 or FIG. 2. Furthermore, a certain materiallayer CLL in the flexible display device 100 used to form wires may beregarded as the other one in FIG. 1 or FIG. 2 (regarded as the secondlayer or the first layer), such that the wires formed by the materiallayer CLL and the pitch of the wire may be regarded as the other one inFIG. 1 or FIG. 2 (regarded as the second patterns and the second pitchor as the first patterns and the first pitch) relative to the assistingpatterns BSP and the pitch Ps. In FIG. 8, the conductive layer formingthe data lines is regarded as the material layer CLL, wherein the source132S and the drain 132D are both formed by the conductive layer, but thepresent disclosure is not limited herein. In the embodiment shown inFIG. 8, the ratio of the first pitch to the second pitch is alsodesigned as being greater than or equal to 2 and less than or equal to200. For example, in this embodiment, when the ratio of the wire pitchformed by the material layer CLL to the pitch Ps is greater than orequal to 2 and less than or equal to 200, the assisting layer BSL may beregarded as the second layer in FIG. 1 or FIG. 2, and the material layermay be regarded as the first layer in FIG. 1 or FIG. 2. In otherembodiments, the pitch Ps of the assisting patterns BSP may be greaterthan the pitch of the wires formed by the material layer CLL. That is tosay, when the ratio of the pitch Ps of the assisting patterns BSP to thepitch of the wires formed by the material layer CLL is greater than orequal to 2 and less than or equal to 200, the assisting layer BSL may beregarded as the first layer in FIG. 1 or FIG. 2, and the material layerCLL may be regarded as the second layer in FIG. 1 or FIG. 2.

Please refer to FIG. 9. FIG. 9 is a partial sectional-view schematicdiagram of a fourth embodiment of an electronic device according to thepresent disclosure. The main difference between the structure shown inFIG. 9 and FIG. 8 is that the assisting layer BSL and the assistingpatterns BSP are disposed on the lower side of the flexible substrate102 and formed on the lower surface 1022 of the flexible substrate 102,and the adhesive layer 122 may directly cover the assisting patternsBSP. In other words, the assisting layer BSL is disposed between theflexible substrate 102 and the adhesive layer 122. In this design, theassisting layer BSL, the assisting patterns BSP and the pitch of theassisting patterns may respectively correspond to the first layer, thefirst patterns and the first pitch in FIG. 1 or FIG. 2, or mayrespectively correspond to the second layer, the second patterns and thesecond pitch in FIG. 1 or FIG. 2. In addition, the selection of anothermaterial layer may be referred to the description of FIG. 8 and FIG. 7,and will not be redundantly described.

Please refer to FIG. 10. FIG. 10 is a partial sectional-view schematicdiagram of a fifth of an electronic device according to the presentdisclosure. In the structure shown in FIG. 10, the assisting layer BSLmay be used as a raster element. In FIG. 10, the assisting layer BSL isused as a wire grid polarizer (WGP) as an example, which may replace thepolarizing layer 126 in the previous embodiment. The assisting layer BSLis disposed on the display layer 114 and the touch layer 120, and thematerial of the assisting layer BSL may for example include molybdenum(Mo), titanium (Ti), tantalum (Ta), niobium (Nb), hafnium (Hf), nickel(Ni), chromium (Cr), cobalt (Co), zirconium (Zr), tungsten (W), aluminum(Al), copper (Cu) and so on or the alloys or combinations of thematerials described above, but not limited herein. An insulating layer146 may be disposed between the assisting layer BSL and theencapsulating layer 142 and the encapsulating layer 144, wherein theinsulating layer 146 may also be a quarter-wavelength phase retarder,but not limited herein. In this embodiment, the assisting patterns BSPhave a smaller pitch Ps, for example, smaller than the pitch of the datalines. Furthermore, the assisting layer BSL, the assisting patterns BSPand the pitch Ps may be regarded as the second layer, the secondpatterns and the second pitch in FIG. 2, and another material layer CLLin the flexible display device 100 may be regarded as the first layer inFIG. 2. For example, the conductive layer used to form the data lines(not symbolized) may be regarded as the first layer, the data lines maybe regarded as the first patterns, and the pitch of the data lines maybe regarded as the first pitch. In this embodiment, the first pitch isgreater than the second pitch, and the ratio of the first pitch to thesecond pitch is greater than or equal to 2 and less than or equal to200. In this embodiment, the second layer is disposed on the firstlayer, the line width of the first pattern is regarded as the firstwidth (e.g., the line width of the data line), and the ratio of thefirst width to the first pitch may be less than the ratio of the secondwidth (the line width Ws) to the second pitch (the pitch Ps). Forexample, the ratio of the first width to the first pitch is greater thanor equal to 0.02 and less than or equal to 0.2, and the ratio of thesecond width to the second pitch is greater than or equal to 0.3 andless than or equal to 3, for example, the ratio of the second width tothe second pitch ranging from 0.3 to 0.8, but the present disclosure isnot limited herein. In an example of the present disclosure, the linewidth Ws may be 150 nanometers (nm) for example, and the pitch Ps may be300 nm for example, so that the ratio of the second width to the secondpitch is 0.5. In another example of the present disclosure, the linewidth Ws may be 80 nm for example, and the pitch Ps may be 200 nm forexample, so that the ratio of the second width to the second pitch is0.4.

Please refer to FIG. 11. FIG. 11 is a partial top-view schematic diagramof examples of assisting patterns of an electronic device according tothe present disclosure. According to the present disclosure, althoughthe assisting patterns BSP extend along a direction (e.g., the directionDy in FIG. 1), the practical patterns of the assisting patterns BSP mayhave different designs, for example having unsmooth sides orconcave-convex edges. In the example (I), the assisting pattern BSP mayhave a linear pattern with substantially smooth two sides. In theexample (II), the assisting pattern BSP may be formed of a plurality ofportions, such as a portion P1 with a shape similar to a rectangular orsquare, a portion P2 with a twist shape and a portion P3 with a longstrip shape or a long rectangular shape, and these three portions aredisposed alternately. For example, one portion P2 is disposed betweentwo portions P1, and two portions P1 are disposed between two portionsP3. In the example (III), the assisting pattern BSP may be formed of aplurality of portions with different shapes, such as portions P4 andportions P6 respectively with a triangle-like shape and a portion P5with a shape similar to a rhombic or an inclined rectangular, whereinthe sharp corner of each portion P4 faces to the right and is disposedon the right side of the portion P5, the sharp corner of each portion P6faces to the left and is disposed on the left side of the portion P5,and the portion P5 is disposed between the portions P4 and the portionsP6. In the example (IV), the sharp corner of each portion P4 faces tothe right and is disposed on the left side of the portion P5, the sharpcorner of each portion P6 faces to the left and is disposed on the rightside of the portion P5, and the portion P5 is disposed between theportions P4 and the portions P6. In the example (V), the assistingpattern BSP may be formed of a plurality of portions with differentshapes, such as a portion P7 with a circle pattern, a portion P8 with anelliptical shape and a portion P9 with a long elliptical shape, whereinthe portion P7 may be disposed between adjacent two or a plurality ofportions P8, and the portions P8 may be disposed between adjacent two ora plurality of portions P9. The assisting patterns BSP of the presentdisclosure is not limited to those shown in FIG. 8, and any suitablepattern designs may be applied to the assisting patterns BSP of thepresent disclosure. It should be noted that, the pitch, the width andthe line spacing of the assisting patterns BSP of the present disclosuremay be designed according to the requirements. For example, in anelectronic device, the assisting patterns BSP may have the same pitch,but the line width and/or the line spacing of each assisting pattern BSPare not completely the same. In another embodiment, the pitch, the linewidth and/or the line spacing of each assisting pattern BSP may not becompletely the same.

Please refer to FIG. 12. FIG. 12 is a partial sectional-view schematicdiagram of a first variant embodiment of an assisting layer of anelectronic device according to the present disclosure. FIG. 12illustrates a cross-sectional shape of an assisting pattern BSP of theassisting layer BSL, wherein the assisting pattern BSP is disposed onthe surface of the substrate 102′, and the substrate 102′ in FIG. 12 maybe represented to include the flexible substrate 102 in FIG. 1 to FIG.10 and any other films on the surface of the flexible substrate. Forexample, the substrate 102′ may selectively include the flexiblesubstrate 102, the circuit layer 112, the light emitting layer 104, theencapsulating layer 142, the encapsulating layer 144 and the insulatinglayer 146, but not limited herein. According to the present disclosure,the assisting layer BSL may be a composite structure. For example, theassisting layer BSL (or the assisting patterns BSP) may be adouble-layer structure or a multi-layer structure including a firstsub-assisting layer BSP1 and a second sub-assisting layer BSP2sequentially disposed on the surface of the substrate 102′, wherein thefirst sub-assisting layer BSP1 has a thickness TH1, and the secondsub-assisting layer BSP2 has a thickness TH2. The thickness TH2 may bedifferent from the thickness TH1, and for example, the thickness TH2 isgreater than the thickness TH1. In some embodiments, the ratio of thetotal thickness Hp of the assisting layer BSL to the maximum line widthWp of the composite structure may be greater than or equal to 0.2 andless than or equal to 2. For example, the material of the firstsub-assisting layer BSP1 may include a material with better adhesionincluding titanium, molybdenum and so on, and the material of the secondsub-assisting layer BSP2 may include a material with better wireextension including aluminum, copper and so on.

Please refer to FIG. 13. FIG. 13 is a partial sectional-view schematicdiagram of a second variant embodiment of an assisting layer of anelectronic device according to the present disclosure. In FIG. 13, theassisting layer BSL (or the assisting pattern BSP) may include athree-layer structure. For example, the assisting layer BSL (or theassisting pattern BSP) may include a first sub-assisting layer BSP1, asecond sub-assisting layer BSP2 and a third sub-assisting layer BSP3 aresequentially disposed on the substrate 102′. A thickness TH2 of thesecond sub-assisting layer BSP2 may be greater than a thickness TH1 ofthe first sub-assisting layer BSP1, and/or the thickness TH2 of thesecond sub-assisting layer BSP2 may be greater than a thickness TH3 ofthe third sub-assisting layer BSP3. For example, the material of thefirst sub-assisting layer BSP1 and the third sub-assisting layer BSP3may include the materials with better adhesion including titanium,molybdenum and so on, and the material of the second sub-assisting layerBSP2 may include a material with better wire extension includingaluminum, copper and so on, but not limited herein.

Please refer to FIG. 14. FIG. 14 is a partial sectional-view schematicdiagram of a third variant embodiment of an assisting layer of anelectronic device according to the present disclosure. The structure ofthis variant embodiment is similar to the structure of FIG. 13. Theassisting layer BSL (or the assisting pattern BSP) may include a firstsub-assisting layer BSP1, a second sub-assisting layer BSP2 and a thirdsub-assisting layer BSP3 sequentially disposed on the substrate 102′,but the difference is that the assisting layer BSL may include anundulating surface BSa with higher heights and lower heights. Forexample, the surface of the second sub-assisting layer BSP2 may havecavities BSb, so the third sub-assisting layer BSP3 disposed on thesecond sub-assisting layer BSP2 forms an uneven surface BSa. In otherwords, the three-layer composite structure of the assisting layer BSLincludes at least two thicknesses, such as a thickness Hp1 and athickness Hp2, wherein the ratio of the maximum thickness Hp1 to themaximum line width Wp of the assisting pattern BSP may be greater thanor equal to 0.2 and less than or equal to 2, but the present disclosureis not limited herein. In some embodiments, the assisting layer BSL canalso be, for example, a multilayer structure, and the multilayerstructure includes at least two or more than two thicknesses, but notlimited herein.

From the above description, the flexible display device of the presentdisclosure at least includes two material layers, one of the materiallayers may be designed as an assisting layer including a plurality ofassisting patterns extending along a direction (e.g., the direction Dy),and the other material layer may select any wire material layer in thedisplay layer or the touch layer of the flexible display device, whereinthe wire material layer includes a plurality of repeated wires of aplurality of parallel assisting patterns, and the pitch and the linewidth of the assisting patterns have a specific relationship with thepitch and the line width of the wires of the wire material layer. Thetwo material layers describe above may be regarded as the first layer orthe second layer in FIG. 1 or FIG. 2 according to the designrequirements, and the ratio of the first pitch to the second pitch isgreater than or equal to 2 and less than or equal to 200. This designmay reduce optical ripple interference, make the assisting patterns toachieve the function of assisting the flexure of the display device, andprovide better display effects.

Please refer to FIG. 15. FIG. 15 is a top-view schematic diagram of anassisting layer of another embodiment of an electronic device accordingto the present disclosure. In the embodiment shown in FIG. 15, theassisting layer BSL may be integrated to the touch layer 120, that is,the touch elements 116 a (represented by thin lines), the touch elements116 a′ (represented by thick lines) or wires in the touch layer 120 maybe used as the assisting patterns BSP. For example, the touch layer 120may include the touch elements 116 a and the touch elements 116 a′ thatare extending along the direction Dy and the touch elements 116 bextending along the direction Dx, wherein the touch elements 116 a andthe touch elements 116 a′ have a pitch Ptx in the direction Dx, and thetouch elements 116 b have a pitch Pty in the direction Dy. According tothe design of the present disclosure, the pitch Ptx is different fromthe pitch Pty. For example, the pitch Pty is greater than the pitch Ptx,or for example (but not limited to), the pitch Pty is twice the pitchPtx. That is to say, the distribution density of the touch elements 116a and the touch elements 116 a′ is greater than the distribution densityof the touch elements 116 b. Since the pitch Ptx is different from thepitch Pty, when the flexible display device 100 is flexed, the flexureeffect of the touch elements 116 a and the touch elements 116 a′ on theflexible display device 100 in the direction Dy is different from theflexure effect of the touch elements 116 b on the flexible displaydevice 100 in the direction Dx. For example, since the pitch Ptx issmaller, it is helpful to make the flexible display device 100 bend in adirection perpendicular to the extending direction of the touch elements116 a′ (e.g., the direction Dy), for example, being bent in a directionDx perpendicular to the direction Dy, and the bent portion may define aflexing axis FX, which is generally parallel to the extending directionof the touch elements 116 a′ (e.g., the direction Dy). The flexibledisplay device 100 may be flexed or bent by taking the flexing axis FXas the axis center. Precisely speaking, the number of the touch elements116 a having the same distance and the number of the touch elements 116b having the same distance are generally the same, so the effect onflexure stress of the touch elements 116 a may offset against the effecton flexure stress of the touch elements 116 b, and both of the touchelements 116 a and the touch elements 116 b may not provide the functionof assisting flexure, but the effect on flexure stress of the touchelements 116 b may not offset against the effect on flexure stress ofthe touch elements 116 a′. Therefore, the touch elements 116 a′ may beregarded as the assisting patterns BSP having a pitch Ps, and the touchlayer 120 may be regarded as the assisting layer BSL of the presentdisclosure. In brief, when the material layer manufactured by the sameprocess has patterns extending in different directions, the patterns inthe two directions may be designed to have different pitches. Forexample, the patterns parallel to the flexing axis FX has a smallerpitch or a larger average distribution density, so that the patterns mayprovide the function of the assisting patterns BSP of the presentdisclosure. In other words, the principle described above may also beapplied to two material layers manufactured by different processes, soas to make the pattern density of one of the material layers parallel tothe flexing axis FX be larger, and this material layer may be used asthe assisting layer BSL. It should be noted that, although the linearpatterns of the touch layer 120 are referred to as the touch elements116 a, the touch elements 116 a′ and the touch elements 116 b, thelinear patterns may also be wires in the touch layer 120 forelectrically connecting the touch elements in different embodiments.

According to the present disclosure, an electronic device including aflexible display device may have an assisting layer, and the assistinglayer may include a plurality of assisting patterns, so as to be helpfulto make the flexible display device be flexed toward a predetermineddirection, and reduce the adverse stress effects in other directions.The difference between the pitch of the assisting patterns and the pitchof other patterns (e.g., the scanning lines or the data lines) in thedisplay device that are generally parallel to the assisting patterns isat least more than twice, and the ratio of the pitch of the assistingpatterns to the pitch of the other patterns described above is greaterthan or equal to 2 and less than or equal to 200. This design may reducethe optical ripple interference and provide better display effects.

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the disclosure. Accordingly, the abovedisclosure should be construed as limited only by the metes and boundsof the appended claims.

What is claimed is:
 1. A flexible display device, comprising: a firstlayer comprising a plurality of first patterns having a first pitch; anda second layer overlapping with the first layer and comprising aplurality of second patterns having a second pitch, wherein a ratio ofthe first pitch to the second pitch is greater than or equal to 2 andless than or equal to 200, one of the plurality of first patterns has afirst width, one of the plurality of second patterns has a second width,and a ratio of the first width to the first pitch is less than a ratioof the second width to the second pitch.
 2. The flexible display deviceaccording to claim 1, wherein the second layer is disposed on the firstlayer.
 3. The flexible display device according to claim 2, wherein thesecond layer is a wire grid polarizer.
 4. The flexible display deviceaccording to claim 1, wherein the ratio of the second width to thesecond pitch is greater than or equal to 0.3 and less than or equal to3.
 5. The flexible display device according to claim 1, furthercomprising a flexible substrate thereon disposed the first layer.